i think two places where KO is lacking is in the discussion of the key count and pivot point, those were the sections i found myself stumbling through the most, specifically what do they exactly mean. I know the book describes the terms, but in retrospect something like a table with what the advantage/expectation at each point would have been nice. also a discussion of when to wong in, like the one on here recently would have added a great deal.
other than that I thought the book was pretty easy to follow. i got tired of reading about gumballs but the book was easy to follow and I started practicing using it within one day of reading it.
i thought all the graphs and math were easy to follow, i found 3 typos in the book, one in a graph, one in some math, and one in the text. none were of serious consequence to understanding the book.
there is a lot to digest in the book, but I think it is presented clearly enough so that one could get started using KO immediately. for me that was the whole point.